CN111698067A - Data transmission method and device - Google Patents

Abstract

The application discloses a data transmission method and device, and belongs to the technical field of communication. The method comprises the following steps: a sending end generates preemption indication information, wherein the preemption indication information is used for indicating whether a preemption mechanism occurs or not; and the transmitting end transmits a PPDU (PPDU), wherein the PPDU comprises a lead code and a data field, and the data field carries the preemption indication information. According to the method and the device, the data field of the PPDU carries the preemption indication information used for indicating whether the preemption mechanism occurs or not, the receiving end can determine whether the preemption mechanism occurs or not according to the preemption indication information, the transmission of the PPDU can be stopped, and the flexibility of data transmission is improved.

Description

Data transmission method and device

technical field

The present application relates to the field of communication technologies, and in particular, to a data transmission method and device.

Background technique

Each network device in the wireless transmission system obtains transmission opportunities through competition. For example, a network device in a wireless local area network (WLAN) competes for a channel through a fallback mechanism, and after contending for a channel, transmits a Physical Layer Protocol Data Unit (PPDU) on the channel. The PPDU includes a preamble and a data field, and the data field is used to carry a medium access control (MAC) protocol data unit (MAC Protocol Data Unit, MPDU) (also referred to as a MAC frame). ), the MAC frame contains data, control signaling or management signaling, etc.

According to the existing WLAN protocol, in the process of transmitting PPDUs with lower service priorities on the channel, the network equipment cannot transmit PPDUs with higher service priorities, resulting in longer transmission delay of PPDUs with higher service priorities and longer data transmission delays. Transmission flexibility is low.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a data transmission method and apparatus, which can solve the problems of long transmission delay and low data transmission flexibility in the related art of PPDUs with higher service priorities. The technical solution is as follows:

In a first aspect, a data transmission method is provided for a sender, the method comprising:

Generate preemption indication information, the preemption indication information is used to indicate whether the preemption mechanism occurs; send a physical layer protocol data unit PPDU, the PPDU includes a preamble and a data field, and the data field carries the preemption indication information.

In the data transmission method provided by the present application, by carrying preemption indication information for indicating whether the preemption mechanism occurs in the data field of the PPDU, when the sender needs to stop transmitting the current PPDU, it can notify the receiver to stop the transmission of the current PPDU through the preemption indication information. Improved data transfer flexibility. When the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU and transmit the data frame with a higher service priority in time, so the service priority can be reduced. Higher data frame transmission delay.

A second aspect provides a data transmission method for a receiving end, the method comprising:

Receive a PPDU, the PPDU includes a preamble and a data field, the data field carries preemption indication information, and the preemption indication information is used to indicate whether a preemption mechanism occurs; based on the preemption indication information, the PPDU is parsed.

In a first possible implementation manner of the second aspect, if the preemption indication information indicates that a preemption mechanism occurs, the parsing the PPDU based on the preemption indication information includes: based on the preemption indication information, determining the The position of the preemptive end symbol in the PPDU, where the preemptive end symbol is used to indicate the transmission end position of the PPDU.

After the receiving end determines the position of the preemptive end symbol in the PPDU, it can determine the transmission end position of the PPDU according to the position of the preemptive end symbol and the number of padding characters indicated by the high throughput control field, so that the receiving end can quickly generate the confirmation information of the PPDU. .

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, the preemptive end symbol is the last OFDM symbol including the target A-MPDU subframe or the target A-MPDU subframe. The last OFDM symbol of the code block where the frame is located, and the target A-MPDU subframe is the last A-MPDU subframe in the PPDU.

In a first possible implementation manner of the first aspect and the second aspect, the preamble includes a traditional signaling L-SIG field, and if a preemption mechanism occurs, the actual transmission duration of the PPDU is less than the length of the L-SIG field. Indicates the original scheduled transmission duration. In other words, when the preemption mechanism occurs, the actual transmission duration of the PPDU is less than the original transmission duration indicated by the L-SIG field.

Wherein, the occurrence of the preemption mechanism means that the sending end suspends the sending of the current frame. The actual transmission duration of the PPDU is less than the original transmission duration indicated by the L-SIG field. In other words, the number of A-MPDU subframes in the actually transmitted PPDU is less than the number of A-MPDU subframes in the originally scheduled transmission the number of frames.

In a second possible implementation manner of the first aspect and the second aspect, the data field includes at least one A-MPDU subframe, and each A-MPDU subframe in the at least one A-MPDU subframe carries the The preemption indication information is described.

In combination with the second possible implementation manner of the first aspect and the second aspect, in the third possible implementation manner of the first aspect and the second aspect, if the preemption mechanism occurs, the last The preemption indication information carried in an A-MPDU subframe indicates that the preemption mechanism occurs.

In combination with the second possible implementation manner or the third possible implementation manner of the first aspect and the second aspect, in a fourth possible implementation manner of the first aspect and the second aspect, the A-MPDU subframe includes MPDU separation symbol and MPDU, the MPDU delimiter includes at least one of an end frame field, a reserved bit field, an MPDU length field, a cyclic redundancy code field, and a delimiter signature field, and the MPDU includes a frame header, a frame body, and a frame check. check at least one field in the sequence,

The preemption indication information is located in the end frame field, the reserved bit field, the MPDU length field, the cyclic redundancy code field, the delimiter signature field, the high throughput control field of the frame header and at least one field in the frame check sequence.

Combining the fourth possible implementation manner of the first aspect and the second aspect, in a fifth possible implementation manner of the first aspect and the second aspect, the preemption indication information is located in the reserved bit field, if the reserved bit If the field is set to a first value, it indicates that the preemption mechanism has occurred; if the reserved bit field is set to a second value, it indicates that the preemption mechanism has not occurred, and the second value is different from the first value.

Combining the fourth possible implementation manner of the first aspect and the second aspect, in a sixth possible implementation manner of the first aspect and the second aspect, the preemption indication information is located in the cyclic redundancy code field, if the The cyclic redundancy code field includes the first type of cyclic redundancy code, which indicates that the preemption mechanism occurs; if the cyclic redundancy code field includes the second type of cyclic redundancy code, it indicates that the preemption mechanism does not occur, and the second type of cyclic redundancy code does not occur. The cyclic redundancy code is different from the cyclic redundancy code of the first type.

Combining the sixth possible implementation manner of the first aspect and the second aspect, in the seventh possible implementation manner of the first aspect and the second aspect, the cyclic redundancy code of the first type is a The cyclic redundancy code is obtained by performing at least one of an XOR operation and a flip operation.

Combining the fourth possible implementation manner of the first aspect and the second aspect, in an eighth possible implementation manner of the first aspect and the second aspect, the preemption indication information is located in the delimiter signature field, if the delimiter If the delimiter signature field includes the first type of delimiter signature symbol, it indicates that the preemption mechanism occurs; if the delimiter signature field includes the second type of delimiter signature symbol, it indicates that the preemption mechanism does not occur, and the second type of delimiter signature The symbol is different from the delimiter signature symbol of the first type.

Combining the fourth possible implementation manner of the first aspect and the second aspect, in a ninth possible implementation manner of the first aspect and the second aspect, the preemption indication information is located in the end frame field and the MPDU length field , if the end frame field is set to 1 and the MPDU length field is set to 0, it indicates that the preemption mechanism occurs.

Combining the fourth possible implementation manner of the first aspect and the second aspect, in a tenth possible implementation manner of the first aspect and the second aspect, the preemption indication information is located in the frame check sequence, if the frame The check sequence includes a sequence of the first type, which indicates that a preemption mechanism occurs; if the frame check sequence includes a sequence of a second type, it indicates that the preemption mechanism does not occur, and the sequence of the second type is different from the sequence of the first type. Wherein, the sequence of the first type may be obtained by performing at least one of an exclusive OR operation and an inversion operation on the sequence of the second type.

In combination with the fourth possible implementation manner of the first aspect and the second aspect, in an eleventh possible implementation manner of the first aspect and the second aspect, the preemption indication information includes at least one of the high throughput control fields. One piece of indication information, the at least one indication information includes at least one of a control identifier, a preemption type, a number of padding symbols, a time to resume transmission, and whether to reply to confirmation information.

With reference to any one of the possible implementation manners of the second to eleventh aspects of the first aspect and the second aspect, in the twelfth possible implementation manner of the first aspect and the second aspect, if a preemption mechanism occurs, the PPDU Also included is at least one of a padding symbol and a data packet extension field following the at least one A-MPDU subframe. Both padding and data packet spreading are used to help increase processing time at the receiving end.

In a thirteenth possible implementation manner of the first aspect and the second aspect, the preamble carries preemption warning information, and the preemption warning information is used to indicate whether a preemption mechanism may occur.

Since the preamble in the PPDU is transmitted before the data field, by carrying preemption warning information in the preamble, it can indicate whether the receiver may have a preemption mechanism during the transmission of the PPDU. If the preemption warning information indicates that the preemption mechanism may occur, the receiver is ready to stop receiving the currently transmitted PPDU at any time; if the preemption warning information indicates that the preemption mechanism cannot occur, the receiver receives the currently transmitted PPDU according to the existing WLAN protocol.

In combination with the thirteenth possible implementation manner of the first aspect and the second aspect, in the fourteenth possible implementation manner of the first aspect and the second aspect, the preemptive warning information is located in the EHT-SIG field of the preamble .

In combination with the second possible implementation manner of the first aspect and the second aspect, in the fifteenth possible implementation manner of the first aspect and the second aspect, if a preemption mechanism occurs, the PPDU further includes a device located in the at least one A - Preemption indication frame following the MPDU subframe. The preemption indication frame can be used by the receiver to determine the end position of the transmission of the PPDU.

In combination with the second possible implementation manner of the first aspect and the second aspect, in a sixteenth possible implementation manner of the first aspect and the second aspect, if a preemption mechanism occurs, the PPDU further includes a device located in the at least one A - A preemption field following the MPDU subframe, the preemption field including at least one special OFDM symbol. Optionally, at least one special OFDM symbol can be used by the receiving end to determine the position where the transmission of the PPDU ends.

In a third aspect, a data transmission method is provided for a sender, the method comprising:

generating preemption indication information, where the preemption indication information is used to indicate the occurrence of the preemption mechanism; sending a PPDU, where the PPDU includes a preamble and a data field, and the data field carries the preemption indication information.

In the data transmission method provided by this application, when the preemption mechanism occurs, the data field of the PPDU carries preemption indication information for indicating the occurrence of the preemption mechanism. When the sender needs to stop transmitting the current PPDU, it can notify the receiver of the current PPDU suspends transmission, which improves the flexibility of data transmission. When the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU and transmit the data frame with a higher service priority in time, so the service priority can be reduced. Higher data frame transmission delay.

A fourth aspect provides a data transmission method for a receiving end, the method comprising:

Receive a PPDU, the PPDU includes a preamble and a data field, the data field carries preemption indication information, and the preemption indication information is used to indicate that a preemption mechanism occurs; based on the preemption indication information, the PPDU is parsed.

In a first possible implementation manner of the third aspect and the fourth aspect, the preamble includes a traditional signaling L-SIG field, and the actual transmission duration of the PPDU is shorter than the original transmission indicated by the L-SIG field duration.

Wherein, the occurrence of the preemption mechanism means that the sending end suspends the sending of the current frame. The actual transmission duration of the PPDU is less than the original transmission duration indicated by the L-SIG field. In other words, the number of A-MPDU subframes in the actually transmitted PPDU is less than the number of A-MPDU subframes in the originally scheduled transmission the number of frames.

In a second possible implementation manner of the third aspect and the fourth aspect, the data field includes at least one A-MPDU subframe and a preemption indication frame located after the at least one A-MPDU subframe, the preemption indication The frame carries the preemption indication information. The preemption indication frame can be used to indicate the occurrence of the preemption mechanism, and can also be used by the receiver to determine the end position of the transmission of the PPDU.

In a second possible implementation manner of the third aspect and the fourth aspect, the data field includes at least one A-MPDU subframe and a preemptive field located after the at least one A-MPDU subframe, the preemptive field including At least one special OFDM symbol, the preemption indication information is located in the preemption field. At least one special OFDM symbol can be used to indicate the occurrence of the preemption mechanism, and can also be used by the receiver to determine the end position of the transmission of the PPDU.

In combination with the second implementation manner of the third aspect and the fourth aspect, in a third implementation manner of the third aspect and the fourth aspect, the special OFDM symbol includes: an OFDM symbol in which only even-numbered subcarriers have energy , an OFDM symbol in which only odd-numbered subcarriers have energy, an OFDM symbol in a predetermined pattern known to the receiving end, an OFDM symbol identical to the previous OFDM symbol, or an OFDM symbol with multiple repetitive waveforms.

In a fourth possible implementation manner of the third aspect and the fourth aspect, the preamble carries preemption warning information, and the preemption warning information is used to indicate whether a preemption mechanism may occur.

Since the preamble in the PPDU is transmitted before the data field, by carrying preemption warning information in the preamble, it can indicate whether the receiver may have a preemption mechanism during the transmission of the PPDU. If the preemption warning information indicates that the preemption mechanism may occur, the receiver is ready to stop receiving the currently transmitted PPDU at any time; if the preemption warning information indicates that the preemption mechanism cannot occur, the receiver receives the currently transmitted PPDU according to the existing WLAN protocol.

In combination with the third aspect and the fourth implementable manner of the fourth aspect, in a fifth implementable manner of the third aspect and the fourth aspect, the preemptive warning information is located in the EHT-SIG field of the preamble.

In a fifth aspect, a data transmission device is provided for a sending end, and the data transmission device has a function of implementing the behavior of the data transmission method in the first aspect. The data transmission apparatus includes at least one module, and the at least one module is configured to implement the data transmission method provided in the first aspect or the third aspect.

In a sixth aspect, a data transmission apparatus is provided for a receiving end, and the data transmission apparatus has a function of implementing the behavior of the data transmission method in the second aspect. The data transmission apparatus includes at least one module, and the at least one module is configured to implement the data transmission method provided in the second aspect or the fourth aspect.

In a seventh aspect, a data transmission device is provided for a sending end, comprising: a memory and a processor, the memory is coupled to the processor, the memory is used for storing a computer program, and the computer program includes program instructions; the processor is used for The program instructions are invoked to implement the data transmission method according to any one of the first aspect or the third aspect.

In an eighth aspect, a data transmission device is provided for a receiving end, comprising: a memory and a processor, the memory is coupled to the processor, the memory is used for storing a computer program, and the computer program includes program instructions ; the processor is configured to invoke the program instructions to implement the data transmission method according to any one of the second aspect or the fourth aspect.

In a ninth aspect, a computer-readable storage medium is provided, the computer-readable storage medium stores a computer program, and the computer program includes at least a piece of code, and the at least one piece of code can be executed by a computer to control the computer to execute the first The data transmission method according to any one of the aspect to the fourth aspect.

A tenth aspect provides a computer program for executing the data transmission method according to any one of the first to fourth aspects when the computer program is executed by a computer.

Optionally, the computer program may be stored in whole or in part on a storage medium packaged with the processor, or may be stored in part or in part in a memory not packaged with the processor.

In an eleventh aspect, a processor is provided, the processor comprising:

at least one circuit for generating preemption indication information or parsing PPDU;

At least one circuit for sending and receiving PPDUs.

Optionally, the above-mentioned processor may be a chip.

In a twelfth aspect, a chip is provided, including a processor for invoking and executing instructions stored in the memory from a memory, so that a communication device installed with the chip executes the methods in the above aspects.

In a thirteenth aspect, the embodiments of the present application further provide another chip, which may be a part of a receiving end or a transmitting end, and the chip includes: an input interface, an output interface, and a circuit, the input interface, the output interface and all The circuits are connected through internal connection paths, and the circuits are used to execute the methods in the above examples.

In the fourteenth aspect, another chip is provided, including: an input interface, an output interface, a processor, and optionally, a memory, wherein the input interface, the output interface, the processor, and the memory pass through an internal The connection paths are connected, and the processor is configured to execute the code in the memory, and when the code is executed, the processor is configured to execute the method in the above-mentioned aspects.

A fifteenth aspect provides an apparatus for implementing the methods of the above aspects.

A sixteenth aspect provides a data transmission system, comprising: a sending end and at least one receiving end, the sending end includes the data transmission device according to the fifth aspect, and the receiving end includes the data transmission device according to the sixth aspect data transmission device.

In the technical solution provided by the present application, when the sender needs to stop transmitting the current PPDU, it can notify the receiver to stop the transmission of the current PPDU through preemption indication information, which improves the flexibility of data transmission. For example, when the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU and transmit the data frame with a higher service priority in time, so the service can be reduced. The transmission delay of data frames with higher priority, thereby improving the reliability of the data transmission system and improving the throughput rate of the data transmission system.

Description of drawings

1 is a schematic structural diagram of a data transmission system provided by an embodiment of the present application;

2 is a schematic diagram of a frame structure of an MPDU provided by an embodiment of the present application;

3 is a schematic structural diagram of an A-MPDU provided by an embodiment of the present application;

4 is a schematic structural diagram of an MPDU separator provided by an embodiment of the present application;

5 is a schematic structural diagram of a PPDU provided by an embodiment of the present application;

6 is a flowchart of a data transmission method provided by an embodiment of the present application;

7 is a schematic diagram of data transmission in a preemptive transmission mode provided by an embodiment of the present application;

8 is a schematic diagram of data transmission under another preemptive transmission mode provided by an embodiment of the present application;

FIG. 9 is a schematic structural diagram of another PPDU provided by an embodiment of the present application;

10 is a schematic structural diagram of another PPDU provided by an embodiment of the present application;

11 is a schematic structural diagram of still another PPDU provided by an embodiment of the present application;

FIG. 12 is a schematic structural diagram of another PPDU provided by an embodiment of the present application;

13 is a schematic structural diagram of a data transmission apparatus provided by an embodiment of the present application;

14 is a schematic structural diagram of another data transmission apparatus provided by an embodiment of the present application;

15 is a schematic structural diagram of a data transmission apparatus provided by another embodiment of the present application;

16 is a schematic structural diagram of another data transmission apparatus provided by another embodiment of the present application;

17 is a block diagram of a data transmission apparatus provided by an embodiment of the present application;

FIG. 18 is a block diagram of another data transmission apparatus provided by an embodiment of the present application.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a data transmission system provided by an embodiment of the present application. As shown in FIG. 1 , the data transmission system includes at least one sending end 101 and at least one receiving end 102, and communication between the sending end 101 and the receiving end 102 can be performed through a wireless network. Referring to FIG. 1 , the embodiment of the present application is described by taking a data transmission system including one transmitting end 101 and two receiving ends 102 as an example.

Optionally, the data transmission system provided in this embodiment of the present application may be a wireless communication system, such as a wireless local area network (wireless LAN, WLAN). The wireless communication system may support various WLAN communication protocols, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11ax protocol, and the next-generation or next-generation protocols of the IEEE 802.11ax protocol. For convenience of description, the embodiment of the present application uses a WLAN as an example for description. A WLAN may include multiple basic service sets (Basic Service Set, BSS), and the nodes of the basic service set include an access point type station (access point, AP) and a non-access point type station (None access point station, Non- AP STA), wherein a station of the access point type is generally referred to as an access point, that is, an AP, and a station of a non-access point type is generally referred to as a station, that is, a STA. Each basic service set may contain one AP and multiple STAs associated with the AP. An access point is a device with a wireless transceiver function that can provide services to a site. A station is a device with wireless transceiver function, which can access a wireless local area network based on an access point.

The AP may also be called a wireless access point or a hotspot. APs are access points for mobile users to access wired networks. They are mainly deployed in homes, buildings, and campuses, with a typical coverage radius ranging from tens of meters to hundreds of meters. Of course, they can also be deployed outdoors. AP is equivalent to a bridge connecting wired network and wireless network. Its main function is to connect various STAs together, and then connect the wireless network to the wired network. Optionally, the AP may be a terminal device or a network device with a wireless fidelity (wireless fidelity, Wi-Fi) chip, for example, the AP may be a communication server, a router, a switch, or a network bridge.

Optionally, the STA may be a wireless communication chip, a wireless sensor or a wireless communication terminal. For example, the STA may be a mobile phone supporting Wi-Fi communication function, a tablet computer supporting Wi-Fi communication function, set-top box supporting Wi-Fi communication function, smart TV supporting Wi-Fi communication function, Wi-Fi communication function supporting smart wearable devices, in-vehicle communication devices that support Wi-Fi communication functions, or computers that support Wi-Fi communication functions, etc.

Optionally, in this embodiment of the present application, the transmitting end 101 may be an AP, and the receiving end 102 may be a STA. Alternatively, the sending end 101 may be an AP, and the receiving end 102 may also be an AP. Alternatively, the transmitting end 101 may be a STA, and the receiving end 102 may also be a STA. The embodiments of the present application are described by taking the transmitting end 101 as an AP and the receiving end 102 as an STA as an example.

In WLAN, data, control signaling or management signaling, etc. are transmitted between AP and STA through MPDU. The MPDU usually includes a frame header, a frame body (Frame Body) and a frame check sequence (Frame Check Sequence, FCS). The frame body is used to carry the data, management information or control information delivered by the upper layer. For some specific types of MPDUs, the frame body may not exist, such as acknowledgment frames. FCS is used to check whether the MPDU is transmitted correctly. The frame header may include a Frame Control (Frame Control) field, a Duration/ID field, an Address Information field, a Sequence Control (Sequence Control) field, a Quality of Service Control (QoS Control) field, and a high throughput At least one of the HighThroughput Control (HT Control) fields. For the explanation of each field, reference may be made to the IEEE802.11 protocol, which will not be repeated in this embodiment of the present application. Exemplarily, FIG. 2 is a schematic diagram of a frame structure of an MPDU provided by an embodiment of the present application. As shown in FIG. 2 , the frame header includes a frame control field, a duration/identity (duration or identification) field, and an address information field (for example, address 1). , Address 2, Address 3 and Address 4), sequence control field, quality of service control field and high throughput control field. It should be noted that FIG. 2 is only used to illustrate the frame structure of the MPDU, and the embodiments of the present application do not limit the content included in the frame header of the MPDU and the arrangement order of each field.

In order to improve WLAN performance, a frame aggregation technology is currently used at the MAC layer to aggregate multiple MPDUs into one aggregated MPDU (Aggregated MPDU, A-MPDU). Since all MPDUs in the same A-MPDU are transmitted by one PPDU, the overhead of the PPDU preamble and the contention channel can be reduced, thereby improving the transmission efficiency. FIG. 3 is a schematic structural diagram of an A-MPDU in the IEEE802.11 standard. As shown in FIG. 3 , the A-MPDU includes n A-MPDU subframes, and n is an integer greater than 1. Optionally, referring to FIG. 3 , the A-MPDU may further include an end of frame (EOF) pad field located after n A-MPDU subframes. Please continue to refer to FIG. 3, each A-MPDU subframe includes an MPDU delimiter (delimiter) and an MPDU. Optionally, the A-MPDU subframe may further include padding fields. The MPDU separator is used to separate multiple aggregated MPDUs.

Optionally, the MPDU delimiter includes at least one of an EOF field, a reserved bit (reserved) field, an MPDU length (MPDUlength) field, a cyclic redundancy code (Cyclic Redundancy Code, CRC) field, and a delimiter signature (delimitersignature) field. . Wherein, EOF is usually used to indicate whether the MPDU is the last MPDU in the A-MPDU. The MPDU length is used to indicate the number of bytes of the MPDU immediately following the current MPDU separator, that is, the MPDU length is used to indicate the number of bytes of the MPDU in the current A-MPDU subframe. The delimiter signature is a characteristic sequence (its ASCII value is 'N'), which is used by the receiver to search for delimiters. Even if the receiver decodes a delimiter or MPDU incorrectly, it can still find the next delimiter signature by searching for the next delimiter signature. MPDU to prevent error propagation. CRC, similar to FCS, is used at the receiving end to check whether the delimiter has an error. It can also determine a sliding window according to the length of the MPDU delimiter. After checking whether the CRC passes, the sliding window is used to find the next MPDU delimiter. Among them, the length of the MPDU delimiter is 4 bytes. Exemplarily, FIG. 4 is a schematic structural diagram of an MPDU separator provided by an embodiment of the present application. As shown in FIG. 4 , the MPDU separator includes an EOF field, a reserved bit field, an MPDU length field, a CRC field, and a separator signature field. . It should be noted that FIG. 2 is only used to illustrate the structure of the MPDU separator, and the embodiments of the present application do not limit the content contained in the MPDU separator and the arrangement order of each field.

It should be noted that the A-MPDU is carried in the data field of the PPDU for transmission. According to the existing WLAN protocol, in the process of sending a PPDU, if the sender needs to transmit a PPDU with a higher service priority, it can only send the PPDU with a higher service priority after the currently sent PPDU is sent. The transmission delay of a PPDU with a higher service priority is longer, so the current data transmission flexibility is lower.

In this application, the preemption mechanism is introduced into the IEEE802.11 standard. When the preemption mechanism occurs during the transmission of a certain PPDU, the sender can stop the transmission of the A-MPDU and transmit the PPDU with higher service priority, so as to reduce the high The transmission delay of business priority improves the flexibility of data transmission. The occurrence of the preemption mechanism means that the transmitting end is suspended from transmitting a PPDU in the process of transmitting the PPDU, and the actual transmission duration of the PPDU is less than the original transmission duration indicated by the legacy signal (L-SIG) field of the PPDU. . The fact that the preemption mechanism does not occur means that the sender transmits the PPDU normally. In this embodiment of the present application, the preemption mechanism may also be referred to as a transmission suspension mechanism. Whether the preemption mechanism occurs or not is used to indicate whether the sender aborts the transmission of the current PPDU.

Optionally, the triggering condition for the preemption mechanism to occur includes that a data frame with a higher service priority preempts a transmission channel of a data frame with a lower service priority, or the sender is required to stop the transmission of the current frame, etc. The triggering conditions for the mechanism to occur are not limited. In the following embodiments of the present application, the data frame with higher service priority preempts the transmission channel of the data frame with lower service priority as an example for triggering the occurrence of the preemption mechanism for description.

For example, both the sender and the receiver provided by the embodiments of the present application may include a queue that can be preempted and a fast queue, and a communication interface exists between the queue that can be preempted and the fast queue for mutual communication. The queue that can be preempted is used for storing preemptable frames, and the express queue is used for storing express frames. A fast frame is a frame with a higher service priority, and a frame that can be preempted is a frame with a lower service priority. Since the delay requirement of a frame with a higher service priority is generally higher than that of a frame with a lower service priority, a fast frame has a higher delay requirement than a frame that can be preempted. Optionally, in the process of sending a frame that includes a frame that can be preempted, when a fast frame needs to be sent, the sender will receive an instruction sent internally by the sender to stop the transmission of the current PPDU, so as to trigger the preemption mechanism to occur, and in the current PPDU. The corresponding signaling information is carried in it, indicating that the receiving end of the PPDU will suspend the transmission.

It should be noted that there is a length indication of the data packet in the preamble of the PPDU. For example, in the legacy signal (L-SIG) field of the preamble, there are a length (length) subfield and a rate (rate) subfield, and the sender uses the length subfield and rate subfield in the L-SIG field Indirectly indicates the original transmission duration of the PPDU. Wherein, the rate subfield is fixedly set to 6 megabits per second (Megabits per second, Mbps), because the rate subfield is set to a fixed value, that is, the original transmission duration of the PPDU is indirectly indicated by the length subfield. The Length calculation formula of the length subfield is as follows:

Among them, SignalExtension (signal extension) is a parameter related to the transmission frequency band. When working at 2.4GHz, the parameter is 6μs (microseconds), and when working at 5GHz, the parameter is 0μs. TXTIME is the original transmission duration of the entire PPDU. The value of m may be 0, 1, or 2, depending on the specific PPDU type, and details are not described herein in this embodiment of the present application.

When the preemption mechanism occurs, the actual transmission duration of the PPDU is less than the duration of the TXTIME corresponding to the Length in the L-SIG field (ie, the original transmission duration). Correspondingly, the receiving end will calculate the receiving duration through the length subfield in the L-SIG field:

Likewise, when the preemption mechanism occurs, the actual transmission duration of the PPDU received by the receiver is less than the duration of RXTIME calculated by Length (ie, the original transmission duration). It should be pointed out that the RXTIME and TXTIME calculated by the Length field may be slightly different due to the actual length of the symbol.

It can be seen from the above content that when the preemption mechanism occurs, the actual transmission duration of the PPDU is less than the original transmission duration indicated by the L-SIG field. It can also be understood that the PPDU is originally intended to transmit n A-MPDU subframes. If the preemption mechanism occurs during the transmission process, the PPDU actually transmits m A-MPDU subframes. Both n and m are positive integers, and m <n.

For example, FIG. 5 is a schematic structural diagram of a PPDU provided by an embodiment of the present application. As shown in FIG. 5 , the PPDU includes a preamble and a data field, and the preamble is used to assist in the reception of the data field. The data field includes a data subfield A and a data subfield B. The data subfield A includes m A-MPDU subframes, and the data subfield B includes (n-m) A-MPDU subframes. Optionally, the data field further includes a data packet extension (PE) field located after the n A-MPDU subframes. If the preemption mechanism occurs, the PPDU actually transmits m A-MPDU subframes in the data subfield A, while (n-m) A-MPDU subframes and the PE field in the data subfield B are not actually transmitted.

It should be noted that, in this embodiment of the present application, the A-MPDU subframe is used as the minimum transmission unit, that is, after the preemption mechanism occurs, m A-MPDU subframes in the n A-MPDU subframes originally scheduled to be transmitted by the PPDU have been sent. (n-m) A-MPDU subframes have not been sent. Since the IEEE802.11 standard stipulates that each MPDU has a clear sequence number index, there is no need for additional fragmentation information indication for the (n-m) A-MPDUs that have not been sent. , and it does not need to correspond to the m A-MPDU subframes that have been sent, and only needs to be carried by a new PPDU and then continue to transmit.

In the embodiment of the present application, the occurrence of the receiver preemption mechanism may be instructed by a MAC method, that is, the occurrence of the receiver preemption mechanism may be instructed in the MAC frame structure; and/or the occurrence of the receiver preemption mechanism may be instructed by a physical method, that is It is in the physical layer structure that the receiver preemption mechanism is indicated to occur. The following embodiments of the present application describe in detail the manner in which the preemption mechanism occurs by using three PPDUs with different structures. The PPDU shown in FIG. 9 and FIG. 10 both correspond to the MAC method, and the PPDU shown in FIG. 11 corresponds to the physical method. For the convenience of description, the related signaling information used to indicate the occurrence of the preemption mechanism is collectively referred to as preemption indication information in this embodiment of the present application.

FIG. 6 is a flowchart of a data transmission method provided by an embodiment of the present application, which can be applied to the data transmission system shown in FIG. 1 . As shown in Figure 6, the method includes:

Step 601: The sender generates preemption indication information.

In an optional embodiment of the present application, the preemption indication information is used to indicate whether the preemption mechanism occurs.

In another optional embodiment of the present application, the preemption indication information is used to indicate that the preemption mechanism occurs.

Step 602: The sender sends a PPDU including a frame that can be preempted.

Wherein, the PPDU includes a preamble and a data field, and the data field carries the preemption indication information.

Step 603: After receiving the PPDU, the first receiver parses the PPDU based on the preemption indication information.

Optionally, if the preemption indication information indicates that the preemption mechanism occurs, the first receiving end may generate confirmation information after parsing the received A-MPDU subframe in the PPDU, and reply the confirmation information to the transmitting end. Further, if the preemption mechanism occurs, the above data transmission method further includes the following processes:

Step 604: The sender sends a PPDU including a fast frame.

If the preemption indication information indicates that the preemption mechanism occurs, the sender sends a PPDU containing a fast frame.

Step 605: After receiving the PPDU including the fast frame, the second receiver parses the PPDU including the fast frame.

Optionally, after parsing the PPDU containing the fast frame, the second receiving end may generate confirmation information of the PPDU containing the fast frame, and reply the confirmation information of the PPDU containing the fast frame to the transmitting end.

Step 606: The transmitting end sends a PPDU that includes the A-MPDU subframes that may be unsent in the preempted frame.

Step 607: After receiving the PPDU including the A-MPDU subframe that can be unsent in the preempted frame, the first receiver parses the PPDU including the A-MPDU subframe that can be unsent in the preempted frame.

Optionally, after the first receiving end parses the PPDU containing the A-MPDU subframe that can be unsent in the preempted frame, it can generate confirmation information that contains the PPDU of the A-MPDU subframe that can be unsent in the preempted frame, And reply the confirmation information of the PPDU including the A-MPDU subframe that can be preempted in the unsent frame to the sender.

It should be noted that the above-mentioned first receiving end and second receiving end may be the same receiving end, or may be different receiving ends, which are not limited in this embodiment of the present application.

Optionally, this embodiment of the present application provides two preemptive transmission modes:

In the first preemptive transmission mode, step 604 and step 606 are performed simultaneously. The transmitting end adopts the orthogonal frequency division multiple access (OFDMA) method or the multi-user multiple input multiple output (MU-MIMO) method to simultaneously transmit the PPDU including the fast frame and the A PPDU containing an A-MPDU subframe that may not be sent in the preempted frame.

It should be noted that adopting the first preemptive transmission mode can reduce the influence of the preemption mechanism on the delay caused by the preempted frame, and can prevent the occurrence of starvation.

In the second preemptive transmission mode, step 604 and step 606 are executed successively. The sender sends PPDUs containing fast frames. Within the current transmission opportunity (TXOP) or the original transmission duration of the preempted PPDU, if the fast frame is transmitted, the sender continues to send PPDUs containing the A-MPDU subframes that may not be sent in the preempted frame; otherwise , the transmitting end re-contends for the channel, and then transmits the PPDU containing the A-MPDU subframes that may not be transmitted in the preempted frame.

For example, it is assumed that the preemptible frame includes the first fragment, the second fragment and the third fragment, and the preemption mechanism occurs after the transmitting end transmits the first fragment of the preemptible frame. Wherein, the first fragment, the second fragment and the third fragment all contain at least one A-MPDU subframe. For example, referring to FIG. 5 , the first fragment contains m A-MPDU subframes in the data subfield A, The union of the A-MPDU subframes contained in the second slice and the third slice is (n-m) A-MPDU subframes in the data subfield B. FIG. 7 is a schematic diagram of data transmission in the first preemptive transmission mode provided by an embodiment of the present application. As shown in FIG. 7 , the transmitting end adopts OFDMA mode or MU-MIMO mode (abbreviation: OFDMA/MU-MIMO) for simultaneous transmission The fast frame in the fast queue and the second slice of the preemptible frame and the third slice of the preemptible frame in the preemptible queue. In addition, a frame aggregation method may also be used to aggregate the second fragment of the frame that can be preempted and the third fragment of the frame that can be preempted into one A-MPDU and then send it. FIG. 8 is a schematic diagram of data transmission in a second preemptive transmission mode provided by an embodiment of the present application. As shown in FIG. 8 , the sender first transmits the fast frames in the fast queue, and then transmits the preemptible queues in the queue that can be preempted. The second slice of the frame and the third slice of the frame that can be preempted.

It should be noted that, the sequence of steps of the data transmission method provided by the embodiments of the present application may be appropriately adjusted, and the steps may be correspondingly increased or decreased according to the situation. Any person skilled in the art who is familiar with the technical scope disclosed in the present application can easily think of any variation of the method, which should be covered by the protection scope of the present application, and thus will not be repeated here.

In the data transmission method provided by the embodiments of the present application, when the sender needs to stop transmitting the current PPDU, it can notify the receiver to stop the transmission of the current PPDU through preemption indication information, which improves the flexibility of data transmission. When the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU and transmit the data frame with a higher service priority in time, so the service priority can be reduced. Higher data frame transmission delay.

In an optional embodiment of the present application, the preemption indication information is used to indicate whether the preemption mechanism occurs. Then, in the PPDU shown in FIG. 5 , each A-MPDU subframe of the data field carries preemption indication information.

For example, FIG. 9 is a schematic structural diagram of another PPDU provided by an embodiment of the present application. As shown in FIG. 9 , the data fields originally scheduled to be transmitted in the PPDU include n A-MPDU subframes and n A-MPDU subframes. PE field after the frame. The first m A-MPDU subframes in the n A-MPDU subframes are located in the data subfield A, and the remaining (n-m) A-MPDU subframes are located in the data subfield B. The m A-MPDU subframes in the data subfield A are the A-MPDU subframes actually transmitted in the PPDU, and the (n-m) A-MPDU subframes in the data subfield B are located after the n A-MPDU subframes The PE field is not actually transmitted.

Optionally, the structure of each A-MPDU subframe can refer to FIG. 3 and FIG. 4, and the preemption indication information is located in the EOF field, the reserved bit field, the MPDU length field, the CRC field, the delimiter signature field, and the high throughput rate of the frame header. Control field and at least one field in FCS.

In a first possible implementation, the preemption indication information is located in a reserved bit field. If the reserved bit field is the first value, it indicates that the preemption mechanism has occurred; if the reserved bit field is the second value, it indicates that the preemption mechanism has not occurred, and the second value is different from the first value. For example, when the reserved bit field is 1, it indicates that the preemption mechanism has occurred; when the reserved bit field is 0, it indicates that the preemption mechanism has not occurred.

By reserving the value of the bit field to indicate whether the preemption mechanism has occurred, the compatibility of data transmission can be guaranteed without adding a new field.

In a second possible implementation manner, the preemption indication information is located in the CRC field. If the CRC field includes a CRC of the first type, it indicates that the preemption mechanism occurs; if the CRC field includes a CRC of the second type, it indicates that the preemption mechanism does not occur, and the CRC of the second type is different from the CRC of the first type.

Optionally, the CRC of the first type is obtained by performing at least one of an XOR operation and an inversion operation on the CRC of the second type, or the type of the CRC of the first type is different from that of the CRC of the second type. For example, when the CRC is generated according to the modulo 2 operation using the polynomial x ⁸ +x ² +x ¹ +1 in the existing IEEE802.11-2016 standard, it means that the preemption mechanism does not occur; when the CRC is subjected to additional XOR operation, for example, perform XOR operation on 8bit CRC with 00001111 to generate xCRC, or use a different polynomial to generate xCRC, indicating that the preemption mechanism occurs.

By carrying different contents in the CRC field to indicate whether the preemption mechanism has occurred, there is no need to add a new field. The receiver can determine whether the preemption mechanism has occurred by analyzing the content of the CRC field, without adding a new amount of computation, ensuring the compatibility of data transmission. At the same time, the data transmission efficiency is guaranteed.

In a third possible implementation, the preemption indication information is located in the delimiter signature field. If the delimiter signature field includes the first type of delimiter signature symbol, the preemption mechanism occurs; if the delimiter signature field includes the second type of delimiter signature symbol, the preemption mechanism does not occur, and the second type of delimiter signature symbol is the same as the The delimiter signature symbols for the first type are different. For example, when the delimiter signature field includes the ASCII code 'N', it indicates that the preemption mechanism does not occur; when the delimiter signature field includes another ASCII code, such as the ASCII code 'Y', it indicates that the preemption mechanism occurs.

By carrying different contents in the delimiter signature field to indicate whether the preemption mechanism occurs, there is no need to add a new field. At the same time of transmission compatibility, data transmission efficiency is guaranteed.

In a fourth possible implementation manner, the preemption indication information is located in the EOF field and the MPDU length field. If the EOF field is set to 1 and the MPDU length field is set to 0, it indicates that EOF padding occurs, indicating that the preemption mechanism occurs.

In a fifth possible implementation manner, the preemption indication information is located in the FCS. If the FCS includes the first type sequence, the characterization preemption mechanism occurs; if the FCS includes the second type sequence, the characterization preemption mechanism does not occur, and the second type sequence is different from the first type sequence. Optionally, the first type sequence is obtained by performing at least one of an exclusive OR operation and a flip operation on the second type sequence, or the types of the first type sequence and the second type sequence are different.

Different types of FCS indicate whether the preemption mechanism occurs, without adding a new field, the receiving end can determine whether the preemption mechanism occurs by parsing the FCS, without adding new calculation amount, while ensuring the compatibility of data transmission, the data is guaranteed. transmission efficiency.

In a sixth possible implementation manner, the preemption indication information includes at least one indication information in the high throughput control field, where the at least one indication information includes a control identifier, preemption type, number of padding symbols, recovery transmission time, and whether a reply is required Confirm at least one of the messages.

The control identifier is used to indicate the type of subsequent control information. The length of the control identifier is 4 bits, and currently 0-6 have been used to indicate other types of control information. If the preemption indication information is carried in the form of control information, the control identifier may be one of 7-15, which is used to indicate that the type of the subsequent control information is preemption indication information. The preemptive type can be defined for the preemptive transmission mode in the IEEE802.11 standard. For example, according to the above two preemptive transmission modes, two preemptive types can be defined. The number of padding symbols is used to indicate the number of padding symbols located after the A-MPDU subframe, and the padding symbols are used to help the receiving end increase processing time. The resumption transmission time is used to indicate when the receiving end can continue to transmit the preempted frame. The receiving end can sleep before the preempted frame can resume transmission according to the resumption transmission time, so as to achieve the effect of energy saving. Whether the confirmation message needs to be replied is used to indicate whether the receiver needs to reply to the confirmation message when the preemption mechanism occurs.

It should be noted that, one or more of the indication information in the above-mentioned high-throughput control field can also be agreed by the sender and the receiver in advance, and the indication is re-indicated when the agreed indication information changes, without the need for each It is carried in the A-MPDU subframe. Alternatively, the indication information in the above-mentioned high throughput control field may be carried in each A-MPDU subframe, which is not limited in this embodiment of the present application.

Optionally, if the preemption mechanism occurs, the preemption indication information carried in the last A-MPDU subframe in the at least one A-MPDU subframe indicates that the preemption mechanism occurs. And the preemption indication information carried in the A-MPDU subframes transmitted before the last A-MPDU subframe all indicate that the preemption mechanism does not occur.

Optionally, if the preemption mechanism occurs, as shown in FIG. 9 , the PPDU may further include at least one of padding symbols and PE fields located after m A-MPDU subframes. Among them, the padding symbol and the data packet extension are both used to help the receiving end to increase the processing time. That is, after transmitting m A-MPDU subframes to the receiving end, the transmitting end may continue to transmit padding symbols and/or PE field contents to the receiving end, so as to increase the processing time of the receiving end.

Optionally, the implementation process of the above step 603 includes: the receiving end determines the position of the preemptive end symbol in the PPDU based on the preemption indication information, and the preemptive end symbol is used to indicate the transmission end position of the PPDU. Wherein, the preemptive end symbol is the last orthogonal frequency division multiplexing (OFDM) symbol including the target A-MPDU subframe or the last OFDM symbol including the code block where the target A-MPDU subframe is located. - The MPDU subframe is the last A-MPDU subframe in the PPDU.

It should be noted that after determining the position of the preemptive end symbol in the PPDU, the receiving end can determine the transmission end position of the PPDU according to the position of the preemptive end symbol and the number of padding characters indicated by the high throughput control field, so that the receiving end can quickly generate Acknowledgment of the PPDU.

Optionally, the receiving end may calculate and obtain the position of the preemptive end symbol based on information such as the rate, the length of the MPDU, and the length of the code block.

For example, when the data field of the PPDU is modulated by binary convolutional coding (BBC), the preemptive end symbol is the last OFDM symbol containing the current A-MPDU subframe (ie, the target A-MPDU subframe). The information bits that can be carried by an OFDM symbol are the number of databits per symbol (N _DBPS ) per symbol, and the information bits carried in the OFDM symbol where the start bit of the MPDU separator of the A-MPDU subframe is located The order is the B1th bit. The MPDU length field in the MPDU separator of the A-MPDU subframe indicates that the length of the A-MPDU subframe is L bytes. Then the preemptive end symbol is the C1th symbol after the first symbol that carries the A-MPDU subframe, and the calculation formula of C1 is as follows:

For example, when N _DBPS is 117, the first symbol of the A-MPDU subframe is the 10th symbol of the data field of the PPDU, and the A-MPDU subframe starts from the 20th bit (the first 19 bits carry the information), that is, B1=20, L indicates 200 bytes, then C1=14. That is, the position of the preemptive end symbol is the 24th symbol of the data field of the PPDU.

In another example, when the data field of the PPDU is modulated by a low density parity check (LDPC), the preemptive end symbol is the code block containing the current A-MPDU subframe (that is, the target A-MPDU subframe). last OFDM symbol. The information bits that can be carried by the OFDM symbol are N _DBPS , and the order of the information bits carried in the OFDM symbol where the start bit of the MPDU separator of the A-MPDU subframe is located is the B1th bit. The MPDU length field in the MPDU separator of the A-MPDU subframe indicates that the length of the A-MPDU subframe is L bytes. The length of the LDPC code block is L LDPC bits, and the code rate is R. The bit where the A-MPDU subframe ends is the B2th bit of the OFDM symbol where it is located, and the B3th bit of the LDPC code block where the A-MPDU subframe ends, and the preemptive end symbol is the C2th bit after the first symbol that carries the A-MPDU subframe. symbol, the calculation formula of C2 is as follows:

Optionally, the sender may also explicitly instruct the receiver to preempt the position of the end symbol. For example, the transmitting end may instruct the receiving end to preempt the ending symbol and there are several OFDM symbols between the currently transmitted OFDM symbol.

In the PPDU provided by the embodiment of the present application, by carrying preemption indication information for indicating whether the preemption mechanism occurs in each A-MPDU subframe, it can explicitly indicate whether the preemption mechanism occurs at the receiver. When the preemption mechanism occurs, the preemption indication information carried in the currently transmitted A-MPDU subframe indicates that the preemption mechanism occurs, and the currently transmitted A-MPDU subframe is also the last A-MPDU subframe transmitted by the PPDU. After receiving the currently transmitted A-MPDU subframe, it can be determined that the preemption mechanism occurs. In addition, when the receiving end receives the currently transmitted A-MPDU subframe, it can also calculate the position of the preemptive end symbol to determine the current PPDU transmission end position, which improves the flexibility of data transmission compared with the related art.

When the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU and transmit the data frame with a higher service priority in time, so the service priority can be reduced. Higher data frame transmission delay.

In another optional embodiment of the present application, the preemption indication information is used to indicate that the preemption mechanism occurs. Then in the PPDU shown in Figure 5, the field located after the data subfield A carries preemption indication information, that is, after the transmitting end transmits the A-MPDU subframe in the data subfield A to the receiving end, Continue to transmit the field carrying the preemption indication information to the receiver.

For example, FIG. 10 is a schematic structural diagram of another PPDU provided by an embodiment of the present application. As shown in FIG. 10 , the data field includes at least one A-MPDU subframe and a preemption indication frame located after the at least one A-MPDU subframe. , the preemption indication frame carries preemption indication information. That is, after transmitting the at least one A-MPDU subframe to the receiving end, the transmitting end continues to transmit the preemption indication frame to the receiving end.

Please continue to refer to FIG. 10 , the data field originally transmitted in the PPDU includes n A-MPDU subframes and a PE field located after the n A-MPDU subframes. The first m A-MPDU subframes in the n A-MPDU subframes are located in the data subfield A, and the remaining (n-m) A-MPDU subframes are located in the data subfield B. The m A-MPDU subframes in the data subfield A are the A-MPDU subframes actually transmitted in the PPDU, and the (n-m) A-MPDU subframes in the data subfield B are located after the n A-MPDU subframes The PE field is not actually transmitted. After transmitting the m A-MPDU subframes in the data subfield A to the receiving end, the transmitting end needs to continue to transmit the preemption indication frame to the receiving end. That is, the PPDU actually transmitted by the sender includes m A-MPDU subframes in the data subfield A and a preemption indication frame.

Optionally, as shown in FIG. 10 , the PPDU may further include at least one of a padding symbol and a PE field after the preemption indication frame. Among them, the padding symbol and the data packet extension are both used to help the receiving end to increase the processing time. That is, after transmitting the preemption indication frame to the receiving end, the transmitting end may continue to transmit the padding symbol and/or the content of the PE field to the receiving end, so as to increase the processing time of the receiving end.

Optionally, the MAC frame type of the preemption indication frame is different from the MAC frame type of any A-MPDU subframe in at least one A-MPDU subframe in the data field, and the MAC frame type of the preemption indication frame may be IEEE802.11. Any of the reserved MAC frame types in the standard. For example, the type value of the preemptive indication frame is set to 0, and the subtype value is set to 7 or 15; for another example, the type value of the preemptive indication frame is set to 1, and the subtype value is set to 0-2 or 15; The frame type value is set to 2, and the subtype value is set to 1, 2, 3, 5, 6, 7, or 13; the type value of the preemption indication frame is set to 3, and the subtype value is set to 2-15. This embodiment of the present application does not limit the MAC frame type of the preemption indication frame.

For another example, FIG. 11 is a schematic structural diagram of still another PPDU provided by an embodiment of the present application. As shown in FIG. 11 , the data field includes at least one A-MPDU subframe and a preemption field located after the at least one A-MPDU subframe , the preemption field includes at least one special OFDM symbol, and the preemption indication information is located in the preemption field, that is, at least one special OFDM symbol located in the preemption field can be used as the preemption indication information.

Please continue to refer to FIG. 11 , the data field originally transmitted in the PPDU includes n A-MPDU subframes and a PE field located after the n A-MPDU subframes. The first m A-MPDU subframes in the n A-MPDU subframes are located in the data subfield A, and the remaining (n-m) A-MPDU subframes are located in the data subfield B. The m A-MPDU subframes in the data subfield A are the A-MPDU subframes actually transmitted in the PPDU, and the (n-m) A-MPDU subframes in the data subfield B are located after the n A-MPDU subframes The PE field is not actually transmitted. After transmitting m A-MPDU subframes in the data subfield A to the receiving end, the transmitting end needs to continue to transmit at least one special OFDM symbol in the preemptive field after the data subfield A to the receiving end. That is, the PPDU actually transmitted by the transmitting end includes m A-MPDU subframes in the data subfield A and at least one special OFDM symbol in the preemption field.

Optionally, as shown in FIG. 11 , the PPDU may further include at least one of a padding symbol and a PE field after the preemption field. Among them, the padding symbol and the data packet extension are both used to help the receiving end to increase the processing time. That is, after transmitting the preemption indication frame to the receiving end, the transmitting end may continue to transmit the padding symbol and/or the content of the PE field to the receiving end, so as to increase the processing time of the receiving end.

Optionally, the above-mentioned special OFDM symbols include: OFDM symbols with energy only for even-numbered subcarriers, OFDM symbols with energy for only odd-numbered subcarriers, OFDM symbols with a predetermined pattern known to the receiving end, and OFDM symbols that are the same as the previous OFDM symbol. symbol or an OFDM symbol with multiple repeating waveforms.

For example, when at least one special OFDM symbol includes an OFDM symbol with energy only on even-numbered subcarriers or an OFDM symbol with energy only on odd-numbered subcarriers, the receiving end can determine whether the preemption mechanism occurs by identifying the energy of each subcarrier. When at least one special OFDM symbol includes a predetermined pattern of OFDM symbols known to the receiver, such as an EHT-LTF symbol, the receiver can determine whether the preemption mechanism occurs by identifying whether the predetermined pattern of OFDM symbols occurs. When at least one special OFDM symbol includes the same OFDM symbol as the previous OFDM symbol, the receiving end can determine whether the preemption mechanism occurs by identifying whether the current OFDM symbol is a duplicate symbol of the previous OFDM symbol. When at least one special OFDM symbol includes an OFDM symbol with multiple repetitive waveforms, such as an HT-STF symbol, the symbol length is 8 microseconds and contains 5 repetition periods of 1.6 microseconds, the receiving end can identify whether there is a Multiple repeating waveforms of OFDM symbols to determine if a preemption mechanism occurs.

In this embodiment of the present application, at least one special OFDM symbol located in the preemptive field includes a combination of one or more of the foregoing OFDM symbols, and may also include a plurality of repeated certain OFDM symbols described above, which is not the case in this embodiment of the present application. Do limit.

Optionally, in the PPDU shown in FIG. 10 and FIG. 11 , the preemption indication frame and the special OFDM symbol can also be used by the receiving end to determine the transmission end position of the PPDU, so that the receiving end can quickly generate the confirmation information of the PPDU. .

In the PPDU provided by the embodiment of the present application, when the preemption mechanism occurs, the preemption indication frame or special OFDM symbol is transmitted after the currently transmitted A-MPDU subframe. After receiving the preemption indication frame or the special OFDM symbol, the receiver can It is determined that the preemption mechanism occurs, and at the same time, the transmission end position of the current PPDU can be determined. Compared with the related art, the flexibility of data transmission is improved.

When the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU and transmit the data frame with a higher service priority in time, so the service priority can be reduced. Higher data frame transmission delay.

The PPDU provided by this embodiment of the present application may carry preemption indication information used to indicate whether the preemption mechanism occurs in each A-MPDU subframe. When the preemption mechanism occurs, the preemption indication information carried in the currently transmitted A-MPDU subframe Indicates that the preemption mechanism occurs. At the same time, a preemption indication frame and/or a special OFDM symbol is transmitted after the currently transmitted A-MPDU subframe. The preemption indication frame and/or the special OFDM symbol can be used by the receiver to determine the end of the transmission of the PPDU. position, so that the receiving end does not need to calculate the position of the preemptive end symbol, which reduces the computational load of the receiving end and reduces the computational load of the receiving end.

Optionally, in the PPDU shown in any one of FIG. 9 to FIG. 11 , the preamble may carry preemptive warning information, and the preemptive early warning information is used to indicate whether a preemption mechanism may occur, that is, the preemptive early warning information is used for It is used to indicate whether the currently transmitted PPDU contains frames that can be preempted. In the PPDU shown in Figure 10, the preemptive warning information is also used to indicate whether the receiving end needs to synchronously identify the preemption instruction frame; in the PPDU shown in Figure 11, the preemptive warning information is also used to indicate whether the receiving end needs to identify the special OFDM symbols.

Since the preamble in the PPDU is transmitted before the data field, by carrying preemption warning information in the preamble, it can indicate whether the receiver may have a preemption mechanism during the transmission of the PPDU. When the preemption warning information indicates that the preemption mechanism may occur, the receiver is ready to stop receiving the currently transmitted PPDU; when the preemption warning information indicates that the preemption mechanism cannot occur, the receiver receives the currently transmitted PPDU according to the existing WLAN protocol.

12 is a schematic structural diagram of another PPDU provided by an embodiment of the present application. As shown in FIG. 12 , the preamble of the PPDU includes a traditional short training field (legacy short training field, L-STF), a traditional long training field Field (legacy long training field, L-LTF), L-SIG field, symbol for auto-detection (symbol for auto-detection), extremely high throughput signaling (extremely high throughput, EHT-SIG) field, extremely high throughput Extremely high throughput short training field (EHT-STF) and extremely high throughput long training field (EHT-LTF). For the content of the data field of the PPDU, reference may be made to any of the PPDUs shown in FIG. 5 and FIG. 9 to FIG. 11 , and details are not described herein in this embodiment of the present application. Optionally, the preemptive warning information may be located in the EHT-SIG field of the preamble.

To sum up, in the data transmission method provided by the embodiments of the present application, when the transmitting end needs to stop transmitting the current PPDU, it can notify the receiving end to stop transmission of the current PPDU through the preemption indication information, which improves the flexibility of data transmission. When the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU and transmit the data frame with a higher service priority in time, so the service priority can be reduced. The higher transmission delay of the data frame, thereby improving the reliability of the data transmission system and improving the throughput rate of the data transmission system.

In a possible implementation manner, by carrying preemption indication information for indicating whether the preemption mechanism occurs in each A-MPDU subframe, the receiver can be explicitly indicated whether the preemption mechanism occurs. When the preemption mechanism occurs, the preemption indication information carried in the currently transmitted A-MPDU subframe indicates that the preemption mechanism occurs, and the currently transmitted A-MPDU subframe is also the last A-MPDU subframe transmitted by the PPDU. After receiving the currently transmitted A-MPDU subframe, it can be determined that the preemption mechanism occurs; in addition, when the receiving end receives the currently transmitted A-MPDU subframe, it can also calculate the position of the preemptive end symbol to determine the current PPDU transmission. end position.

In another possible implementation manner, when the preemption mechanism occurs, by transmitting the preemption indication frame or special OFDM symbol after the currently transmitted A-MPDU subframe, after the receiver receives the preemption indication frame or the special OFDM symbol, The occurrence of the preemption mechanism can be determined, and the position where the transmission of the current PPDU ends can also be determined.

Therefore, in this embodiment of the present application, when the sender needs to transmit a data frame with a higher service priority in the process of transmitting a certain PPDU, it can suspend the transmission of the current PPDU, and transmit the data with a higher service priority in time. frames, so the transmission delay of data frames with higher service priorities can be reduced.

FIG. 13 is a schematic structural diagram of a data transmission apparatus provided by an embodiment of the present application. The data transmission apparatus can be used for the sending end in FIG. 1 , and the data transmission apparatus 130 includes:

A generating module 1301, configured to generate preemption indication information, where the preemption indication information is used to indicate whether the preemption mechanism occurs;

The sending module 1302 is configured to send a PPDU, where the PPDU includes a preamble and a data field, and the data field carries the preemption indication information.

FIG. 14 is a schematic structural diagram of another data transmission apparatus provided by an embodiment of the present application. The data transmission apparatus can be used for the receiving end in FIG. 1 , and the data transmission apparatus 140 includes:

The receiving module 1401 is configured to receive a PPDU, the PPDU includes a preamble and a data field, the data field carries preemption indication information, and the preemption indication information is used to indicate whether the preemption mechanism occurs;

The parsing module 1402 is configured to parse the PPDU based on the preemption indication information.

The embodiment of the present application takes the data transmission device shown in Each module in the transmission device is explained. It should be understood that the data transmission device used for the transmitting end in the embodiment of the present application has any function of the transmitting end in the data transmission method shown in FIG. 6 , and the data transmission device used for the receiving end has any function of the receiving end in the data transmission method shown in FIG. 6 . Function.

FIG. 15 is a schematic structural diagram of a data transmission apparatus provided by another embodiment of the present application. The data transmission apparatus can be used for the sending end in FIG. 1 , and the data transmission apparatus 150 includes:

A generating module 1501, configured to generate preemption indication information, where the preemption indication information is used to indicate that a preemption mechanism occurs;

The sending module 1502 is configured to send a PPDU, where the PPDU includes a preamble and a data field, and the data field carries the preemption indication information.

FIG. 16 is a schematic structural diagram of another data transmission apparatus provided by another embodiment of the present application. The data transmission apparatus can be used for the receiving end in FIG. 1 , and the data transmission apparatus 160 includes:

A receiving module 1601, configured to receive a PPDU, the PPDU includes a preamble and a data field, the data field carries preemption indication information, and the preemption indication information is used to indicate that the preemption mechanism occurs;

The parsing module 1602 is configured to parse the PPDU based on the preemption indication information.

The embodiments of the present application take the data transmission device shown in FIG. 15 as an example to describe each module in the data transmission device for the sending end, and take the data transmission device shown in FIG. 16 as an example to describe the data transmission device used for the receiving end. Each module in the transmission device is explained. It should be understood that the data transmission device used for the transmitting end in the embodiment of the present application has any function of the transmitting end in the data transmission method shown in FIG. 6 , and the data transmission device used for the receiving end has any function of the receiving end in the data transmission method shown in FIG. 6 . Function.

The data transmission device (used for the sending end or the receiving end) provided in the embodiments of the present application can be implemented in various product forms. For example, the data transmission device can be configured as a general processing system; for example, the data transmission device can be implemented by a general bus architecture; for example, the data transmission device may be implemented by an application specific integrated circuit (ASIC), and so on. Several possible product forms of the data transmission device in the embodiments of the present application are provided below. It should be understood that the following are only examples, and the possible product forms of the embodiments of the present application are not limited thereto.

As a possible product form, the data transmission apparatus 170 may be a device for transmitting data (eg, a base station, UE, or AP, etc.). As shown in FIG. 17 , the data transmission apparatus 170 may include a processor 1701 and a transceiver 1702 ; optionally, the data transmission apparatus may further include a memory 1703 . The processor 1701, the transceiver 1702, and the memory 1703 communicate with each other through internal connections. For example, the data transmission device 170 may further include a bus 1704 through which the processor 1701 , the transceiver 1702 and the memory 1703 communicate with each other. The processor 1701 is configured to execute the processing steps in the method executed by the data transmission apparatus in the method shown in FIG. 6 . For example, when the data transmission device is used at the sending end, the processing steps may be step 601 in FIG. 6; when the data transmission device is used at the receiving end, the processing steps may be steps 603 and 605 in FIG. 4 and step 607. The transceiver 1702, under the control of the receiving processor 1701, is configured to perform the steps of sending and receiving PPDUs in the method performed by the data transmission apparatus in the method shown in FIG. 6 . For example, when the data transmission device is used for the sending end, the sending and receiving steps may be steps 602, 604 and 606 in FIG. 6; when the data transmission device is used for the receiving end, the sending and receiving steps may be the receiving end receiving Steps of PPDU. The memory 1703 is used for storing instructions, which are called by the processor 1701 to execute the processing steps in the method executed by the data transmission apparatus in the method shown in FIG. 6 .

As another possible product form, the data transmission device is also implemented by a general-purpose processor, which is commonly known as a chip. As shown in FIG. 18 , the data transmission device may include: a processing circuit 1801, an input interface 1802 and an output interface 1803. The processing circuit 1801, the input interface 1802, and the output interface 1803 communicate with each other through internal connections; wherein, the input interface 1802 is used to obtain The information to be processed by the processing circuit 1801, the processing circuit 1801 is used to perform the processing steps (eg step 601) performed by the transmitting end in FIG. 6 to process the information to be processed, and the output interface 1803 is used to output the information processed by the processing circuit 1801; or , the input interface 1802 is used to obtain the information to be processed by the processing circuit 1801 (the PPDU received by the receiving end in the embodiment shown in FIG. 6 ), and the processing circuit 1801 is used to execute the processing steps performed by the receiving end in FIG. 6 (for example, step 603 , Step 605 and Step 607) to process the information to be processed, and the output interface 1803 is used to output the information processed by the processing circuit.

Optionally, the data transmission apparatus may further include a transceiver (not shown in FIG. 18 ). Wherein, when the processing circuit 1801 is used to process the information to be processed by executing the processing steps performed by the transmitting end in FIG. 6 , the output interface 1803 is used to output the information processed by the processing circuit 1801 to the transceiver, and the transceiver is used to send the processing circuit 1801 processed information. When the processing circuit 1801 is used to perform the processing steps performed by the receiving end in FIG. 6 to process the information to be processed, the transceiver is used to receive the information to be processed by the processing circuit 1801 and send the information to be processed by the processing circuit 1801 to the input interface 1802 .

As another possible product form, the data transmission device can also be implemented using the following: Field-Programmable Gate Array (FPGA), Programmable Logic Device (PLD), controller, state computer, gate logic, discrete hardware components, etc., any other suitable circuit, or any combination of circuits capable of performing the various functions described throughout this application.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The computer program instructions, when loaded and executed on a computer, result in whole or in part of the processes or functions described herein. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server or data center Transmission to another website site, computer, server, or data center by wire (eg, coaxial cable, optical fiber, or digital subscriber line) or wireless (eg, infrared, wireless, or microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that includes an integration of one or more available media. The usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVD), or semiconductor media (eg, Solid State Disk), among others.

The term "and/or" in this application is only an association relationship to describe associated objects, which means that there can be three kinds of relationships, for example, A and/or B, which can mean that A exists alone, A and B exist at the same time, independently There are three cases of B. In addition, the character "/" in this document generally indicates that the related objects are an "or" relationship.

The above descriptions are only optional embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection of the present application. within the range.

Claims (28)

1. A data transmission method, used at a transmitting end, the method comprising:

generating preemption indication information, wherein the preemption indication information is used for indicating whether a preemption mechanism occurs or not;

and sending a physical layer protocol data unit (PPDU), wherein the PPDU comprises a lead code and a data field, and the data field carries the preemption indication information.

2. A data transmission method, for a receiving end, the method comprising:

receiving a PPDU (PPDU), wherein the PPDU comprises a lead code and a data field, the data field carries preemption indication information, and the preemption indication information is used for indicating whether a preemption mechanism occurs or not;

and resolving the PPDU based on the preemption indication information.

3. The method of claim 2, wherein resolving the PPDU based on the preemption indication information if the preemption indication information indicates that a preemption mechanism occurs comprises:

determining a position of a preemption ending symbol in the PPDU based on the preemption indication information, wherein the preemption ending symbol is used for indicating a transmission ending position of the PPDU.

4. The method of claim 3, wherein the preemptive end symbol is a last Orthogonal Frequency Division Multiplexing (OFDM) symbol containing a target A-MPDU subframe or a last OFDM symbol containing a code block in which a target A-MPDU subframe is located, and wherein the target A-MPDU subframe is a last A-MPDU subframe in the PPDU.

5. The method of any one of claims 1 to 4, wherein the preamble comprises a legacy signaling L-SIG field,

if the preemption mechanism occurs, the actual transmission duration of the PPDU is less than the predetermined transmission duration indicated by the L-SIG field.

6. The method of any of claims 1 to 5, wherein the data field comprises at least one aggregate media access control protocol data unit, A-MPDU, sub-frame, each of the at least one A-MPDU sub-frame carrying the preemption indication information.

7. The method of claim 6, wherein if a preemption mechanism occurs, preemption indication information carried by a last A-MPDU sub-frame of the at least one A-MPDU sub-frame indicates that a preemption mechanism occurs.

8. The method of claim 6 or 7, wherein the A-MPDU sub-frame comprises an MPDU delimiter and an MPDU, wherein the MPDU delimiter comprises at least one of an end frame field, a reserved bit field, an MPDU length field, a cyclic redundancy code field, and a delimiter signature field, wherein the MPDU comprises at least one of a frame header, a frame body, and a frame check sequence,

the preemption-indication information is located in at least one of the end frame field, the reserved bit field, the MPDU length field, the cyclic redundancy code field, the delimiter signature field, a high throughput control field of the frame header, and the frame check sequence.

9. The method of claim 8, wherein the preemption indication information is in the reservation bit field,

if the reserved bit field is a first value, representing that a preemption mechanism occurs;

if the reserved bit field is a second value, indicating that a preemption mechanism does not occur, the second value being different from the first value.

10. The method of claim 8, wherein the preemption indication information is located in the frame check sequence,

if the frame check sequence comprises a first type sequence, characterizing that a preemption mechanism occurs;

if the frame check sequence comprises a second type sequence, characterizing that a preemption mechanism does not occur, the second type sequence being different from the first type sequence.

11. The method of claim 10, wherein the first type sequence is obtained by performing at least one of an exclusive-or operation and a flip operation on the second type sequence.

12. The method of claim 8, wherein the preemption indication information is located in the delimiter signature field,

characterizing that a preemption mechanism occurs if the delimiter signature field includes a delimiter signature symbol of a first type;

characterizing a preemption mechanism does not occur if the delimiter signature field comprises a second type of delimiter signature symbol, the second type of delimiter signature symbol being different from the first type of delimiter signature symbol.

13. The method according to any of claims 1 to 12, wherein the preamble carries pre-emptive warning information, and the pre-emptive warning information is used to indicate whether a pre-emptive mechanism is likely to occur.

14. The method of claim 13, wherein the preemptive early warning information is located in an extremely high throughput signaling (EHT-SIG) field of the preamble.

15. A data transmission apparatus, configured to be used at a transmitting end, the apparatus comprising:

the system comprises a generation module, a pre-emption module and a pre-emption module, wherein the generation module is used for generating pre-emption indication information which is used for indicating whether a pre-emption mechanism occurs or not;

a sending module, configured to send a physical layer protocol data unit PPDU, where the PPDU includes a preamble and a data field, and the data field carries the preemption indication information.

16. A data transmission apparatus, for a receiving end, the apparatus comprising:

a receiving module, configured to receive a PPDU, where the PPDU includes a preamble and a data field, and the data field carries preemption indication information, where the preemption indication information is used to indicate whether a preemption mechanism occurs;

and the analysis module is used for analyzing the PPDU based on the preemption indication information.

17. The apparatus of claim 16, wherein if the preemption indication information indicates that a preemption mechanism is occurring, the parsing module is configured to:

determining a position of a preemption ending symbol in the PPDU based on the preemption indication information, wherein the preemption ending symbol is used for indicating a transmission ending position of the PPDU.

18. The apparatus of claim 17, wherein the preemptive end symbol is a last Orthogonal Frequency Division Multiplexing (OFDM) symbol comprising a target A-MPDU sub-frame or a last OFDM symbol comprising a code block in which a target A-MPDU sub-frame is located, and wherein the target A-MPDU sub-frame is a last A-MPDU sub-frame in the PPDU.

19. The apparatus of any one of claims 15 to 18, wherein the preamble comprises a legacy signaling (L-SIG) field,

if the preemption mechanism occurs, the actual transmission duration of the PPDU is less than the predetermined transmission duration indicated by the L-SIG field.

20. The apparatus of any of claims 15 to 19, wherein the data field comprises at least one aggregate media access control protocol data unit, a-MPDU, sub-frame, each of the at least one a-MPDU sub-frame carrying the preemption indication information.

21. The apparatus of claim 20, wherein the preemption indication information carried by a last a-MPDU sub-frame of the at least one a-MPDU sub-frame indicates that a preemption mechanism is occurring if the preemption mechanism is occurring.

22. The apparatus of claim 20 or 21, wherein the A-MPDU sub-frame comprises an MPDU delimiter and an MPDU, the MPDU delimiter comprising at least one of an end frame field, a reserved bits field, an MPDU length field, a cyclic redundancy code field, and a delimiter signature field, the MPDU comprising at least one of a frame header, a frame body, and a frame check sequence,

the preemption-indication information is located in at least one of the end frame field, the reserved bit field, the MPDU length field, the cyclic redundancy code field, the delimiter signature field, a high throughput control field of the frame header, and the frame check sequence.

23. The apparatus of claim 22, wherein the preemption indication information is in the reservation bit field,

if the reserved bit field is a first value, representing that a preemption mechanism occurs;

if the reserved bit field is a second value, indicating that a preemption mechanism does not occur, the second value being different from the first value.

24. The apparatus of claim 22, wherein the preemption indication information is located in the frame check sequence,

if the frame check sequence comprises a first type sequence, characterizing that a preemption mechanism occurs;

if the frame check sequence comprises a second type sequence, characterizing that a preemption mechanism does not occur, the second type sequence being different from the first type sequence.

25. The apparatus of claim 24, wherein the first type sequence is obtained by performing at least one of an exclusive-or operation and a flip operation on the second type sequence.

26. The apparatus of claim 22, wherein the preemption indication information is located in the delimiter signature field,

characterizing that a preemption mechanism occurs if the delimiter signature field includes a delimiter signature symbol of a first type;

characterizing a preemption mechanism does not occur if the delimiter signature field comprises a second type of delimiter signature symbol, the second type of delimiter signature symbol being different from the first type of delimiter signature symbol.

27. The apparatus according to any of claims 15 to 26, wherein the preamble carries pre-emptive warning information, and the pre-emptive warning information is used to indicate whether a pre-emptive mechanism is likely to occur.

28. The apparatus of claim 27, wherein the preemption pre-warning information is in a very high throughput signaling (EHT-SIG) field of the preamble.

Images